Preliminary studies indicate that low temperature has a differential effect upon the proliferation of transformed mammalian cells. These studies are being extended to test the effects of altering the physical state of the membrane lipids. Electron spin resonance (ESR) studies indicate that surface membranes of higher cells are asymmetric physically. These studies are being extended to see if the asymmetry indeed indicates different physical properties for the inner and outer monolayers of the bilayer. The physical studies include x-ray diffraction experiments. Attempts will be made to identify the cell surface receptors which become enriched in phagosomes to beads to which lectins are attached. In this fashion, we can test the hypothesis that numerous receptors are attached to microfilaments which underlie the membrane. To this effect we will use transformed, colchicine treated cells, where lectin receptors can apparently be patched on the cell surface. A computer program is being developed to assess cell surface receptor distribution, e.g. clustering. This program will be used to assess alterations in lectin receptor distribution following exposure of cells to cold and alteration of cells by transformation.